Binding branched and linear DNA structures: from isolated clusters to fully bonded gels

The proper design of DNA sequences allows for the formation of well defined supramolecular units with controlled interactions via a consecution of self-assembling processes. Here, we benefit from the controlled DNA self-assembly to experimentally realize particles with well defined valence, namely tetravalent nanostars (A) and bivalent chains (B). We specifically focus on the case in which A particles can only bind to B particles, via appropriately designed sticky-end sequences. Hence AA and BB bonds are not allowed. Such a binary mixture system reproduces with DNA-based particles the physics of poly-functional condensation, with an exquisite control over the bonding process, tuned by the ratio, r, between B and A units and by the temperature, T. We report dynamic light scattering experiments in a window of Ts ranging from 10{\deg}C to 55{\deg}C and an interval of r around the percolation transition to quantify the decay of the density correlation for the different cases. At low T, when all possible bonds are formed, the system behaves as a fully bonded network, as a percolating gel and as a cluster fluid depending on the selected r.Comment: 15 pages, 11 figure

Metabolic and hormonal control of energy utilization and partitioning from early to mid lactation in Sarda ewes and Saanen goats

In a recent study, we observed that starch-rich diets used in mid lactation induced lower milk production persistency and higher body fat accumulation in dairy ewes compared with dairy goats. Because these species differences could be linked to hormonal mechanisms that drive energy partitioning, in the same experiment, we explored the evolution of metabolic and hormonal status during lactation to test this hypothesis. Twenty mature Sarda dairy ewes and 20 mature Saanen goats [15\u2013134 \ub1 11 d in milk (DIM), mean \ub1 SD] were compared simultaneously. In early lactation, each species was allocated to one dietary treatment: high-starch diet [HS: 20.4% starch, on dry matter (DM) basis], whereas from 92 \ub1 11 DIM, each species was allocated to 1 of 2 dietary treatments: HS (20.0% starch, on DM basis) and low-starch (LS: 7.8% starch, on DM basis) diets. Blood samples were collected in the morning to analyze glucose, nonesterified fatty acids (NEFA), growth hormone (GH), insulin, and insulin-like growth factor I (IGF-I). Data were analyzed using the PROC MIXED procedure of SAS with repeated measurements (SAS Version 9.0). The HS and LS diets applied in mid lactation did not affect metabolic status of the animal within species; thus, only a comparison between species was carried out. From early to mid lactation, plasma glucose concentration was higher in ewes than in goats (54.57 vs. 48.35 \ub1 1.18 mg/dL), whereas plasma NEFA concentration was greater in goats than in ewes (0.31 vs. 0.25 \ub1 0.03 mmol/L). Goats had higher plasma GH concentration and lower plasma insulin content than ewes (4.78 vs. 1.31 ng/mL \ub1 0.47; 0.11 vs. 0.26 \u3bcg/L \ub1 0.02). Plasma IGF-I concentration did not vary between species. The comparison of metabolic and hormonal status of lactating Sarda dairy ewes and Saanen goats, carried out by studying simultaneously the 2 species in the same stage of lactation and experimental conditions, suggests that the higher insulin and glucose concentration observed in Sarda ewes explains why they partitioned more energy toward body reserves than to the mammary gland, especially in mid lactation. This can justify the negative effect of high-starch diets in mid-lactating Sarda ewes. Conversely, the highest GH and NEFA concentration observed in Saanen goats explain why they partitioned more energy of starch diets toward the mammary gland than to body reserves and justify the positive effect of high-starch diet in mid lactation. Together, these different responses contribute to explain why specialized dairy goats, such as the Saanen breed, have a higher milk production persistency than specialized dairy sheep breeds, such as the Sarda

The clinico-radiological paradox of cognitive function and MRI burden of white matter lesions in people with multiple sclerosis: a systematic review and meta-analysis.

Moderate correlation exists between the imaging quantification of brain white matter lesions and cognitive performance in people with multiple sclerosis (MS). This may reflect the greater importance of other features, including subvisible pathology, or methodological limitations of the primary literature.To summarise the cognitive clinico-radiological paradox and explore the potential methodological factors that could influence the assessment of this relationship.Systematic review and meta-analysis of primary research relating cognitive function to white matter lesion burden.Fifty papers met eligibility criteria for review, and meta-analysis of overall results was possible in thirty-two (2050 participants). Aggregate correlation between cognition and T2 lesion burden was r = -0.30 (95% confidence interval: -0.34, -0.26). Wide methodological variability was seen, particularly related to key factors in the cognitive data capture and image analysis techniques.Resolving the persistent clinico-radiological paradox will likely require simultaneous evaluation of multiple components of the complex pathology using optimum measurement techniques for both cognitive and MRI feature quantification. We recommend a consensus initiative to support common standards for image analysis in MS, enabling benchmarking while also supporting ongoing innovation

Effects of dietary NDF concentration on milk yield and composition in dairy goats in mid-late lactation

Fourteen Sarda goats in mid-late lactation were housed in individual pens where they received a common total mixed ration (TMR) during the preliminary period (21 d). During the experimental period (24 d) the goats were divided in two isoproductive groups and fed differentiated TMR: one group received a high NDF-low no fibre carbohydrate (NFC) total mixed ration (H-NDF diet = 44.7% NDF, 29.3% NFC, DM basis), while the other received a low NDF-high NFC total mixed ration (L-NDF diet = 36.9% NDF, 36.0% NFC, DM basis). These differences were achieved substituting ground corn and barley grains with beet pulp shreds and soybean hulls. Both diets contained 50% of dehydrated chopped alfalfa on a DM basis. Soybean meal completed the diets. Dry matter intake was higher in the H-NDF group, while dietary energy intake and body weight variations did not differ significantly between the two groups. Milk yield was significantly higher in the L-NDF group, while milk protein and milk urea were higher in the H-NDF group. Milk fat concentration and somatic cell count did not differ between groups, while milk fat and milk protein yields were higher in the L-NDF group. These results are in clear contrast to what was previously observed in sheep, fed diets similar to the ones used here, in which H-NDF diets induced higher milk yield than L-NDF ones

Monitoring of chemical elements and oxidative damage in patients affected by Alzheimer's disease

The haematic concentration of 26 metals and the oxidative damage in 60 patients (20 males and 40 females) affected by Alzheimer's disease and 44 healthy individuals (33 males and 11 females) were compared. In patients, the following significant (p ≤ 0.05) discrepancies were found: i) increment of Ca, Cd, Hg, Mg, Si and Sn, and decrement of Al, Co, Fe and Zn in serum; ii) higher concentrations of Cu, Li, Mn, Sn and Zr and lower of Fe, Hg, Mo in blood; iii) overproduction of oxidant species (SOS) and decrease of the anti-oxidant capacity (SAC) (p ≤ 0.001, for both). Variables that, joined, better discriminated between patients and controls resulted to be Si, SOS, SAC, Co, Ca, Al in serum (94% of cases correctly classified) and Cu, Zr, Mo and Fe in blood (90% of cases properly categorized)

Pseudomonas aeruginosa quale responsabile di mastiti ovine: valutazione dei profili di patogenicità in isolati provenienti da allevamenti di diverse aree della Sardegna.

Mastitis affects every year a quantity of animals in the dairy sheep farming in Sardinia. Most cases of clinical ovine mastitis are caused by Gram-positive cocci, but a significant proportion of cases are due to Gram-negative bacteria such as Pseudomonas aeruginosa. We investigated 36 samples of Pseudomonas aeruginosa, coming from ovine milk and milking machines in 11 sardinian farms. Antimicrobial resistance of bacterial strains ( MBC minimal bactericidal concentration ) and biofilm formation were tested. The aim is to evaluate the sensitivity of different bacterial strains to the most common antimicrobials and analyse the potential role of these drugs in the conversion of P. aeruginosa to its mucoid form, which allows it to be more resistant to antimicrobials and antibiotic